Bump @nestjs/mapped-types from 2.0.5 to 2.1.0 in /backend

Bumps [@nestjs/mapped-types](https://github.com/nestjs/mapped-types) from 2.0.5 to 2.1.0.
- [Release notes](https://github.com/nestjs/mapped-types/releases)
- [Changelog](https://github.com/nestjs/mapped-types/blob/master/.release-it.json)
- [Commits](nestjs/mapped-types@2.0.5...2.1.0)

---
updated-dependencies:
- dependency-name: "@nestjs/mapped-types"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>